CS5451A 6-Channel Delta-Sigma A/D Converter
14Pages

CS5451A ANALOG CHARACTERISTICS (continued) Parameter Symbol Min Typ Max Unit Power Supplies Power Supply Currents Typical VA+=VD+ = +3V; VA- = -2 V Ia+ ID+ with CPD PSCA PSCD - 4.0 5.0 5.3 6.3 mA mA ID+ without CPD PSCD - 1.0 1.5 mA Power Consumption (Note 2) With CPD Without CPD PC PC - 27 23 35 31 mW mW Power Supply Rejection 50, 60 Hz (Note 3) (DC) Voltage Channel PSRR PSRR 50 50 65 - dB dB 50, 60 Hz (Note 3) Current Channel PSRR 60 90 - dB Notes: 1. Specifications for Gain = 20 apply only to Current Channels. Voltage Channels are fixed to Gain = 1 2. All outputs unloaded. All inputs...

CS5451A SWITCHING CHARACTERISTICS Min/Max characteristics and spթcifications are guaranteed over all Operating Conditions. Typical characteristics and specifications are measured at nominal supply voltages and TA = 25 °C. Օ VA+ = VD+ = 3 V ±10%; VA- = -2 V ±10%; AGND = DGND = 0 V. All voltages with respect to 0 V. Logic Levels: Logic 0 = 0 V, Logic 1 = VD+ Parameter Symbol Min Typ Max Unit Rise Times Any Digital Input (except XIN) - - 1.0 Ms (Note 6) XIN only trise - - 10 ns Any Digital Output - 50 - ns Fall Times Any Digital Input (except XIN) - - 1.0 Ms (Note 6) XIN only fall - - 10 ns...

CS5451A ABSOLUTE MAXIMUM RATINGS WARNING: Opration at or beyond these limits may result in permanent damage to the device. Normal operation is not guaranteed at these extremes. Parameter Symbol Min Typ Max Unit DC Power Supplies Positive Digital VD+ -0.3 +3.5 V Positive Analog VA+ -0.3 +3.5 V Negative Analog VA- -2.5 -0.3 V Input Current, Any Pin Except Supplies (Note 10 and 11) IIN - - ±10 mA Output Current IOUT - - ±25 mA Power Dissipation (Note 12) PDN - - 500 mW Analog Input Voltage All Analog Pins VINA (VA-) - 0.3 - (VA+) + 0.3 V Digital Input Voltage All Digital Pins VIND -0.3 - (VD+)...

CS5451A 3. THEORY OF OPERATION The CS5451A is a six-channel analog-to-digital convert-er (ADC) followed by a serial interface that allows communication with a target device. The analog inputs are structured for 3-phase power meter applications, with three dedicated voltage and current channels. Figure 2 illustrates the CS5451A typical inputs and power supply connections. The voltage-sensing element introduces a voltage waveform on the voltage channel inputs VIN(1-3)+ and is subject to a fixed 1x gain amplifier. A fourth-order delͭta-sigma modulator samples the amplified signal for...

CS5451A 4. FUNCTIONAL DESCRIPTION 4.1 Analog Inputs The CS5451A is equipped with six fully differential input channels. The inputs VIN(1-3)+ and IIN(1-3)± are des-ignated as the voltage and current channel inputs, re-spectively. The full-scale differential input voltage for the current and voltage channel is +800 mVP (gain = 1x). 4.1.1 Voltage Channel The output of the line voltage resistive divider or transformer is connected to the VIN(1-3)+ and VIN(1-3)- in-put pins of the CS5451A. The voltage channels are equipped with a 1x fixed gain amplifier. The full-scale signal level that can be...

CS5451A 96 SCLKs -H SCLK FSO 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 15 14 13 12 11 10 9 8 7 6 5 3 2 1 0 SDO JOOOOOOOOOOOOOOOOOOOOOOOOO ■ ■ OOOOOOOOOOOOL [ Low ] Channel 1 ( V ) Channel 1(I ) Ch. 2 ( V )...Ch. 2 ( I )... Ch. 3 ( V )...Ch. 3 ( I ) [ Low ] Figure 3. One Data Frame When data is not being transferred SCLK is held low. (see Figure 3.) The framing signal (FSO) output is normally low. FSO goes high, with a pulse width equal to one SCLK period, when the instantaneous voltage and current data sam-ples are about to be transmitted out of the serial interface (after each A/D conversion...